Sensing and Control

Introduction

Sensors and advanced electronics technology are fast becoming a staple of modern consumer technology, enabling greater ease of use, more convenience, and higher levels of efficiency than ever before. But while sensors have found uses in many consumer goods, some important and ubiquitous products have not seen their benefits. One such set of products is white goods. This group of home appliances, which includes clothes washers, dryers, dishwashers, stoves, and refrigerators, is only now capitalizing on sensor technology and advanced control algorithms to deliver an intelligent product to consumers.

In 1995, Maytag introduced the first "smart" dishwasher. This machine relies on a unique set of sensors and a fuzzy logic control algorithm to continuously monitor the harsh environment inside a dishwasher and intelligently direct the dishwasher to save time, water, and energy without compromising the quality of the wash. The product, dubbed IntelliSense Quiet Plus™ by Maytag, was the result of a collaboration between that company and a team of engineers and marketing professionals from Honeywell Micro Switch and Honeywell Technology Center (HTC).

Our contribution to this "intelligent" dishwasher is a sensor module that integrates four sensors into a single housing disposed inside the dishwasher pump to continuously sense load conditions, process the information, and pass it along to a controller to update system decisions according to need. This technology breaks the industry paradigm of fixed, time-based cycles and results in substantial savings of energy and water.

Driving the development of smart appliances such as Maytag’s IntelliSense dishwasher are new federal regulations governing energy and water use by home appliances, machines responsible for a significant percentage of energy and water use in the average home. For dishwashers, these tough new standards from the U.S. Department of Energy (DOE) can only be met by turning to advanced sensors and controls. These new standards are intended to reduce the amount of energy consumed in the U.S. by approximately 2.25 quadrillion BTUs by the year 2015. The next round of standards will be announced in 1996 for appliances built after January 1, 1999.

Against this backdrop, in 1991 a Honeywell team including Micro Switch, HTC, and Newhouse personnel initiated a study of the appliance industry called White Goods 2000. The objective was to look ahead 10 years in the appliance industry and determine whether Honeywell could play a strategic role in helping OEMs meet these tough new standards. We found that the soon-to-be-imposed federal regulations would require white goods manufacturers to turn to sensors and advanced control techniques to meet the new standards. In addition, environmental awareness in Europe was reflected in European consumers’ increasing preference for "green" appliances, even at a cost premium, and U.S. appliance makers were also apprehensive about Japanese entry into the market with advanced technology offerings.

Clothes washers and dishwashers were identified as likely to be the hardest hit by these new standards. Because efficiency ratings for these appliances also include the energy required to heat any water used, water consumption is an area that appliance manufacturers are targeting as a main contributor to making appliances more efficient. It was thought that the best way to save water would be to eliminate excessive cycles, and therefore water, by sensing the soil content of the load. Sensor technology to accomplish this task had been under development at HTC since early 1991.

To be able to really understand the issues the appliance makers were facing, Micro Switch chose to seek an appliance partner. A co-destiny relationship with Maytag was formed in early 1992. This partnership, established to provide a win-win situation for both companies, placed Honeywell in the role of sensor and control expert to support product development at Maytag. Maytag proposed the "smart" dishwasher as a product they wanted to develop. Moreover, they not only wanted to look at sensor technology, they also wanted to incorporate fuzzy logic control. Even more importantly, they wanted to reach a new level of value for the consumer by adding these new technologies to the product.